Flender is rounding off its range of N-Arpex couplings, first introduced in 2017, with two new designs featuring eight and ten bolting points. N-Arpex now covers a diameter up to 988 mm and a torque up to 2,000,000 Nm. The compact design and enhanced bore capacities also enable a leap in size. A smaller coupling transmits a higher torque compared to the predecessor model Arpex. Flender thus further optimises the price-performance ratio. The torsionally rigid all-steel disc coupling is suitable for use in drive applications including pumps, fans, compressors, generators, turbines, and paper and printing machines.

A new, more compact Flender conical bolt connection for the plate packs enable quick and easy installation of the N-Arpex couplings, especially in high torque ranges. This new addition enhances the power density of the N-Arpex series. The revised component first appeared in 2017 with the ARN-6 type. Its compact design and enhanced bore capacities already ensured an optimal ratio between torque and use of materials.

With the two new N-Arpex couplings, Flender has introduced a modular system which increases the number of available types as well as simultaneously reducing the number of components required. The three standard series of the predecessor Arpex merge into one N-Arpex series. This standardization simplifies storage, making the couplings more readily available and reducing spare parts complexity for the pump users.

The new series of couplings has also been designed for use in potentially explosive environments as defined in directive 2014/34/EU and fulfil the requirements of API610/ISO13709 and API671/ISO10441. N-Arpex all-steel couplings are designed as standard for use at very low temperatures down to – 50 °C. With these all-steel couplings, transmission of torque between the machine shafts accompanied by displacement compensation is backlash-free, torsionally rigid and flexible. This enables them to simultaneously compensate for axial, angular and radial offset. The N-Arpex coupling plate packs are made of stainless spring steel, are not subject to wear and are therefore maintenance-free.